This disclosure relates generally to the field of cybersecurity for automation and control systems that are monitored and/or controlled over public or private internet protocol (IP) networks. More specifically, it relates to devices and methods for providing secure communications to and from one or more supervisor control and data acquisition (SCADA) devices in such automation and control systems.
Supervisor Control and Data Acquisition (SCADA) devices, such as switches, meters, and sensors, enable real-time monitoring and control of automation and control systems over public or private internet protocol (IP) networks. Most SCADA devices utilize industrial communication protocols, such as Modbus or Distributed Network Protocol V3.0 (DNP3), which are not designed with robust built-in security. Thus, these networked devices may be susceptible to cyber-terrorism and other malicious attacks that can shut down operations and cause damage to physical equipment. Potential attacks include social engineering, malware, buffer overflow, input validation and man-in-the-middle attacks, from internal or external networks, whether connected to private local networks or the public Internet. This poses a serious cyber-security challenge and risk to critical infrastructure in many industries, such as, for example, petroleum refining, natural gas processing, chemical processing, power generation and distribution, water purification, and even financial institutions.
FIG. 1 illustrates a conventional SCADA network 10 of automation and control devices. The network 10 includes a plurality of SCADA devices 12 linked to an external or remote SCADA control terminal 14 by a network communication device 16, such as, for example, a router. Communication between the remote terminal 14 and the communication device 16 may be through the Internet (as shown), or alternatively, through a Local Area Network (LAN) or a Wide Area Network (WAN). A local or internal SCADA control terminal 18 may also be linked to the SCADA devices 12 and the external control terminal 14 by the communication device 16.
Commercially available options exist for providing a degree of security for networks such as the network 10 shown in FIG. 1. Some options, that operate at the transport layer or higher, such as firewalls, security proxies, intrusion detection systems, and application layer solutions, do not provide physical network segregation. Physical and data-link layer specific solutions, such as network segregation, do not protect against attacks that originate from the internal\segregated network, and they present additional integration issues for SCADA control networks. None of these solutions are able to provide real-time protection for SCADA devices that can be customized for the industrial process and system for which they are installed.
Accordingly, a solution has been sought to the problem of ensuring cyber-security for SCADA networks by protecting them from both internal and external attacks and threats. Moreover, it would be advantageous to provide such protection bi-directionally; that is, by protecting both incoming data (data coming into the SCADA devices from the network with which the device is linked) and outgoing data (data communicated from the SCADA devices to the network).